Originally posted by SunRazer
Firstly, Grievous is far, far stronger than Rey.
Yes of course he is, that's why Shaak was thrown back by it and Kylo wasn't.
Secondly, deflecting the blow bare-handed is better - perhaps far better - than blocking it with a Force shield.
First of all she never deflected anything, just absorbed the momentum of the blade. Secondly, even if she did it why would that be better?
And you seem to have it the other way around. Shaak blocked its cutting power, since she was unharmed, but the kinetic power still affected her, hence she was thrown back.
It's not because she was unharmed that she blocked it's cutting power, she TK-wise stopped the blade from touching her by slowing it's momentum, that's something entirely different.
That said, her Deflection feat would've pertained to the kinetic force of the blow nonetheless - she merely couldn't stop the force of the blow from sending her flying.
Now you're mixing things up, this is just a simple example of Newton's second law of motion. It's the same if you throw a ball (let's name it ball 1) against ball 2 (which is laying still), you'll see that ball 1 is now laying still and ball 2 is on the move because his kinetic energy is transferred from ball 1 to ball 2. This is the same what happened with Shaak, she stopped Grievous his swing from touching her by slowing it down to the point it was still but by doing so (like in the previous mentionend example) all the kinetic energy was transferred from Grievous swing to Shaak Ti and so becuase of that she was thrown back by it, there is no absorbing the lightsaber's cutting power involved since it never even touched her.
PS If you really insist I can write it down in mathematical forumulas 😉